Subject: [PATCH 4/8] pseries: phyp dump: register dump area.

From: Manish Ahuja <[email-masked]>
Date: Fri, 21 Mar 2008 18:43:15 -0500

Set up the actual dump header, register it with the hypervisor.

Signed-off-by: Manish Ahuja <[email-masked]>
Signed-off-by: Linas Vepstas <[email-masked]>

---
 arch/powerpc/platforms/pseries/phyp_dump.c |  137 +++++++++++++++++++++++++++--
 1 file changed, 131 insertions(+), 6 deletions(-)

Index: 2.6.25-rc1/arch/powerpc/platforms/pseries/phyp_dump.c
===================================================================
--- 2.6.25-rc1.orig/arch/powerpc/platforms/pseries/phyp_dump.c	2008-03-21 22:39:21.000000000 -0500
+++ 2.6.25-rc1/arch/powerpc/platforms/pseries/phyp_dump.c	2008-03-21 22:52:53.000000000 -0500
@@ -29,6 +29,117 @@
 static struct phyp_dump phyp_dump_vars;
 struct phyp_dump *phyp_dump_info = &phyp_dump_vars;
 
+static int ibm_configure_kernel_dump;
+/* ------------------------------------------------- */
+/* RTAS interfaces to declare the dump regions */
+
+struct dump_section {
+	u32 dump_flags;
+	u16 source_type;
+	u16 error_flags;
+	u64 source_address;
+	u64 source_length;
+	u64 length_copied;
+	u64 destination_address;
+};
+
+struct phyp_dump_header {
+	u32 version;
+	u16 num_of_sections;
+	u16 status;
+
+	u32 first_offset_section;
+	u32 dump_disk_section;
+	u64 block_num_dd;
+	u64 num_of_blocks_dd;
+	u32 offset_dd;
+	u32 maxtime_to_auto;
+	/* No dump disk path string used */
+
+	struct dump_section cpu_data;
+	struct dump_section hpte_data;
+	struct dump_section kernel_data;
+};
+
+/* The dump header *must be* in low memory, so .bss it */
+static struct phyp_dump_header phdr;
+
+#define NUM_DUMP_SECTIONS	3
+#define DUMP_HEADER_VERSION	0x1
+#define DUMP_REQUEST_FLAG	0x1
+#define DUMP_SOURCE_CPU		0x0001
+#define DUMP_SOURCE_HPTE	0x0002
+#define DUMP_SOURCE_RMO		0x0011
+
+/**
+ * init_dump_header() - initialize the header declaring a dump
+ * Returns: length of dump save area.
+ *
+ * When the hypervisor saves crashed state, it needs to put
+ * it somewhere. The dump header tells the hypervisor where
+ * the data can be saved.
+ */
+static unsigned long init_dump_header(struct phyp_dump_header *ph)
+{
+	unsigned long addr_offset = 0;
+
+	/* Set up the dump header */
+	ph->version = DUMP_HEADER_VERSION;
+	ph->num_of_sections = NUM_DUMP_SECTIONS;
+	ph->status = 0;
+
+	ph->first_offset_section =
+		(u32)offsetof(struct phyp_dump_header, cpu_data);
+	ph->dump_disk_section = 0;
+	ph->block_num_dd = 0;
+	ph->num_of_blocks_dd = 0;
+	ph->offset_dd = 0;
+
+	ph->maxtime_to_auto = 0; /* disabled */
+
+	/* The first two sections are mandatory */
+	ph->cpu_data.dump_flags = DUMP_REQUEST_FLAG;
+	ph->cpu_data.source_type = DUMP_SOURCE_CPU;
+	ph->cpu_data.source_address = 0;
+	ph->cpu_data.source_length = phyp_dump_info->cpu_state_size;
+	ph->cpu_data.destination_address = addr_offset;
+	addr_offset += phyp_dump_info->cpu_state_size;
+
+	ph->hpte_data.dump_flags = DUMP_REQUEST_FLAG;
+	ph->hpte_data.source_type = DUMP_SOURCE_HPTE;
+	ph->hpte_data.source_address = 0;
+	ph->hpte_data.source_length = phyp_dump_info->hpte_region_size;
+	ph->hpte_data.destination_address = addr_offset;
+	addr_offset += phyp_dump_info->hpte_region_size;
+
+	/* This section describes the low kernel region */
+	ph->kernel_data.dump_flags = DUMP_REQUEST_FLAG;
+	ph->kernel_data.source_type = DUMP_SOURCE_RMO;
+	ph->kernel_data.source_address = PHYP_DUMP_RMR_START;
+	ph->kernel_data.source_length = PHYP_DUMP_RMR_END;
+	ph->kernel_data.destination_address = addr_offset;
+	addr_offset += ph->kernel_data.source_length;
+
+	return addr_offset;
+}
+
+static void register_dump_area(struct phyp_dump_header *ph, unsigned long addr)
+{
+	int rc;
+	ph->cpu_data.destination_address += addr;
+	ph->hpte_data.destination_address += addr;
+	ph->kernel_data.destination_address += addr;
+
+	do {
+		rc = rtas_call(ibm_configure_kernel_dump, 3, 1, NULL,
+				1, ph, sizeof(struct phyp_dump_header));
+	} while (rtas_busy_delay(rc));
+
+	if (rc)
+		printk(KERN_ERR "phyp-dump: unexpected error (%d) on "
+						"register\n", rc);
+}
+
 /* ------------------------------------------------- */
 /**
  * release_memory_range -- release memory previously lmb_reserved
@@ -107,7 +218,9 @@ static struct kobj_attribute rr = __ATTR
 static int __init phyp_dump_setup(void)
 {
 	struct device_node *rtas;
-	const int *dump_header = NULL;
+ 	const struct phyp_dump_header *dump_header = NULL;
+ 	unsigned long dump_area_start;
+ 	unsigned long dump_area_length;
 	int header_len = 0;
 	int rc;
 
@@ -119,7 +232,13 @@ static int __init phyp_dump_setup(void)
 	if (!phyp_dump_info->phyp_dump_configured)
 		return -ENOSYS;
 
-	/* Is there dump data waiting for us? */
+	/* Is there dump data waiting for us? If there isn't,
+	 * then register a new dump area, and release all of
+	 * the rest of the reserved ram.
+	 *
+	 * The /rtas/ibm,kernel-dump rtas node is present only
+	 * if there is dump data waiting for us.
+	 */
 	rtas = of_find_node_by_path("/rtas");
 	if (rtas) {
 		dump_header = of_get_property(rtas, "ibm,kernel-dump",
@@ -127,17 +246,23 @@ static int __init phyp_dump_setup(void)
 		of_node_put(rtas);
 	}
 
-	if (dump_header == NULL)
+	dump_area_length = init_dump_header(&phdr);
+
+	/* align down */
+	dump_area_start = phyp_dump_info->init_reserve_start & PAGE_MASK;
+
+	if (dump_header == NULL) {
+		register_dump_area(&phdr, dump_area_start);
 		return 0;
+	}
 
 	/* Should we create a dump_subsys, analogous to s390/ipl.c ? */
 	rc = sysfs_create_file(kernel_kobj, &rr.attr);
-	if (rc) {
+	if (rc)
 		printk(KERN_ERR "phyp-dump: unable to create sysfs file (%d)\n",
 									rc);
-		return 0;
-	}
 
+	/* ToDo: re-register the dump area, for next time. */
 	return 0;
 }
 machine_subsys_initcall(pseries, phyp_dump_setup);